Video: Dab tsi yog qhov kev sib raug zoo database qauv?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
A kev sib txheeb database yog ib txheej ntawm kev piav qhia rooj los ntawm qhov twg cov ntaub ntawv tuaj yeem nkag tau lossis rov sib dhos hauv ntau txoj kev sib txawv yam tsis tas yuav hloov kho lub cov ntaub ntawv database . Tus txheej txheem neeg siv thiab daim ntawv thov programming interface (API) ntawm a kev sib txheeb database yog Structured Query Language (SQL).
Tsuas yog li ntawd, qhov kev sib raug zoo yog dab tsi?
kev sib raug zoo qauv . (cov ntaub ntawv qauv ) Definition: Qhov sib piv ntawm cov logic ntawm cov ntaub ntawv qauv los yog chav kawm piv txwv nyob rau hauv qhov kev xav-oriented. Piv txwv yog cov hlua, cov duab qhia, thiab cov duab tsis qhia. Teeb ntawm Cov qauv kev sib raug zoo generalize txoj kev xav ntawm cov lus raws li cov kab lus.
Tsis tas li ntawd, dab tsi yog qhov kev sib raug zoo database query piav nrog piv txwv? A kev sib txheeb database yog ib pawg ntawm cov rooj uas muaj cov ntaub ntawv haum rau hauv pawg predefined. Rau piv txwv , atypical lag luam xaj nkag database yuav suav nrog lub rooj uas piav qhia tus neeg siv khoom nrog cov kab npe, chaw nyob, xov tooj, thiab lwm yam.
Ntxiv mus, koj txhais li cas los ntawm tus qauv kev sib raug zoo?
Cov kev sib raug zoo qauv (RM) rau kev tswj hwm cov ntaub ntawv yog ib txoj hauv kev los tswj cov ntaub ntawv siv cov qauv thiab cov lus raws li kev txiav txim thawj zaug predicate logic, thawj zaug tau piav qhia nyob rau hauv 1969 los ntawm Askiv computer kws tshawb fawb Edgar F. Codd, qhov twg tag nrho cov ntaub ntawv yog sawv cev nyob rau hauv cov nqe lus ntawm tuples, pab pawg neeg rau hauv. kev sib raug zoo.
Cov qauv kev sib raug zoo nrog piv txwv yog dab tsi?
Hauv kev sib raug zoo qauv , cov ntaub ntawv thiab kev sib raug zoo yog sawv cev los ntawm kev sau ntawm cov rooj sib tham. Txhua lub rooj yog ib pawg ntawm kab thiab kab, qhov twg kab sawv cev rau tus cwj pwm ntawm ib qho chaw thiab kab sawv cev rau cov ntaub ntawv. Qauv kev sib raug zoo Qauv : Cov tub ntxhais kawm lub rooj nrog 3 kab thiab plaub cov ntaub ntawv.
Pom zoo:
Dab tsi yog qhov txawv ntawm cov khoom taw qhia cov qauv database thiab cov qauv kev sib raug zoo?
Qhov sib txawv ntawm kev sib raug zoo database thiab cov khoom taw qhia cov ntaub ntawv yog tias cov ntaub ntawv sib txheeb cov ntaub ntawv khaws cov ntaub ntawv nyob rau hauv daim ntawv ntawm cov ntxhuav uas muaj kab thiab kab. Hauv cov khoom taw qhia cov ntaub ntawv cov ntaub ntawv khaws cia nrog rau nws cov haujlwm uas ua los yog nyeem cov ntaub ntawv uas twb muaj lawm. Cov no yog qhov sib txawv hauv paus
Vim li cas kev sib raug zoo algebra siv nyob rau hauv kev sib raug zoo database tswj?
RELATIONAL ALGEBRA yog ib hom lus nug uas siv dav heev. Nws sau cov xwm txheej ntawm kev sib raug zoo raws li kev tawm tswv yim thiab muab qhov tshwm sim ntawm kev sib raug zoo raws li cov zis. Nws siv ntau yam haujlwm los ua qhov haujlwm no. Relational algebra operations yog ua recursively ntawm kev sib raug zoo
Dab tsi yog qhov txawv ntawm kev sib raug zoo unary kev sib raug zoo binary thiab kev sib raug zoo ternary?
Kev sib raug zoo tsis sib xws yog thaum ob tus neeg koom hauv kev sib raug zoo yog tib lub koom haum. Piv txwv li: Cov ncauj lus yuav yog qhov yuav tsum tau ua ua ntej rau lwm yam kev kawm. Kev sib raug zoo ternary yog thaum peb lub koom haum koom nrog kev sib raug zoo
Dab tsi yog qhov txawv ntawm kev sib raug zoo thiab tsis muaj kev sib raug zoo databases?
Qhov sib txawv loj ntawm lawv yog li cas lawv tuav cov ntaub ntawv. Relational databases are structured.Non-relational databases are document-oriented. Qhov no hu ua cov ntaub ntawv hom cia tso cai ntau 'qeb' ntawm cov ntaub ntawv khaws cia hauv ib qho kev tsim lossis Cov Ntaub Ntawv
Dab tsi yog qee qhov tsis zoo ntawm lub sijhawm stamping txoj hauv kev rau kev tswj hwm kev sib raug zoo?
Qhov tsis zoo ntawm lub sij hawm stamping mus kom ze yog tias txhua tus nqi khaws cia hauv cov ntaub ntawv yuav tsum muaj ob lub sij hawm thwj ntxiv: ib qho rau lub sijhawm kawg ntawm daim teb tau nyeem thiab ib qho rau qhov hloov tshiab kawg. Lub sij hawm stamping yog li ua rau kom nco xav tau thiab cov ntaub ntawv ua haujlwm nyiaj siv ua haujlwm